PA66 plastic has a high melting point in polyamide materials. It is a semi crystalline crystalline material. PA66 can also maintain strong strength and stiffness at higher temperatures. PA66 plastic is still hygroscopic after molding, and its degree mainly depends on the composition of the material, wall thickness and environmental conditions. In product design, the influence of Hygroscopicity on geometric stability must be considered. In order to improve the mechanical properties of PA66, various modifiers are often added. Glass is the most common additive. Sometimes synthetic rubber is added to improve impact resistance. PA66 plastic has low viscosity, so it has good fluidity (but not as good as PA6). This property can be used to process very thin components. Its viscosity is sensitive to temperature changes. The shrinkage of PA66 is between 1% and 2%, and the addition of glass fiber additive can reduce the shrinkage to 0.2% and 1%. The difference of shrinkage in the process direction and the direction perpendicular to the process direction is large. The melting point of PA66 plastic is the temperature of crystallization and melting. For crystalline polymer PA66 plastic, it shows a clear melting point. According to the test method adopted, the melting point fluctuates in the range of 259~267 ℃. The melting point of PA66 plastic measured by differential thermal analysis is 264 ℃. If the temperature at which the coefficient of volume expansion shows a maximum is taken as the melting point, the melting point temperature range of nylon-66 is 246~263 ℃. It is close to the theoretical melting temperature of 259 ℃. Injection molding characteristics of PA66 plastic drying treatment: if the material is sealed before processing, then there is no need to dry. However, if the storage container is opened, it is recommended to dry it in hot air at 85 ℃. If the humidity is greater than 0.2%, vacuum drying at 105 ℃ for 12 hours is also required. Melting temperature: 260~290 ℃. For glass additives, the product temperature is 275~280 ℃. Melting temperature should be avoided higher than 300 ℃. Mold temperature: 80 ℃ is recommended. Mold temperature will affect the crystallinity, which will affect the physical properties of the product. For thin-walled plastic parts, if the mold temperature is lower than 40C, the crystallinity of the plastic parts will change with time. In order to maintain the geometric stability of the plastic parts, annealing treatment is required. Injection pressure: usually 750~1250bar, depending on the material and product design. Injection speed: high speed (slightly lower for reinforced materials). Runner and gate: because the solidification time of PA66 is very short, the position of gate is very important. The gate aperture should not be less than 0.5 * t (where t is the thickness of plastic parts). If hot runner is used, the gate size should be smaller than that of conventional runner, because hot runner can help prevent premature solidification of material. If a submerged gate is used, the minimum diameter of the gate should be 0.75mm. Application of PA66 plastic PA66 is the product with the highest mechanical strength and the most widely used in PA series. Due to its high crystallinity, its rigidity and heat resistance are high. High temperature electrical socket parts, electrical parts, gears, bearings, rollers, spring supports, pulleys, bolts, impellers, fan blades, propellers, high-pressure sealing gaskets, valve seats, oil pipelines, oil storage containers, ropes, ties, transmission belts, grinding wheel adhesives, battery boxes Insulated electrical parts, wire cores, taps, etc.